The naturally occurring, fibrous, magnesium silicate mineral which is commonly referred to as asbestos has long been used for thermal insulation, most often in high-temperature service or where fireproofing is required. However, air-borne fibers and other particles of asbestos have proved to be a major lung irritant capable of causing the serious and frequently fatal disease known as asbestosis among chronically exposed workers. An especially potent hazard has arisen in connection with such confined regions as building crawl spaces, tunnels, and storage areas which have dirt floors and where asbestos has been installed as furnace pipe insulation, steel girder insulation and the like. In these confined spaces, asbestos particles can readily be deposited inadvertently on the dirt floor during repair work activities for example. In other instances, asbestos may have contaminated the soil prior to or during building construction. In either event, the asbestos-laden soil thereafter serves as a permanent source of atmospheric recontamination, sometimes when protective breathing devices are erroneously thought to be unnecessary. In addition, paving over such contaminated soil with concrete or asphalt has proved exceptionally costly and sometimes physically impractical.